All-electric Mini E for 2019 to appear at Frankfurt show in concept form

The first Mini E, cobbled together by putting a battery pack where the rear seat used to be, was BMW's very first attempt at building a modern electric car.

Only a few hundred were built, back in 2009, but the quick project gave the German company real-world experience on how electric-car drivers used their cars, recharged them, and otherwise treated them.

Last fall, BMW's CEO confirmed that an all-electric Mini would return to the British maker's lineup; now, it's rumored to debut in concept form next month at the Frankfurt auto show.

That report comes from the British magazine Autocar, which suggests we'll see a concept for the future Mini E at next month’s 2017 Frankfurt auto show.

It is expected to preview both design elements and technical aspects that will differentiate the electric Two-Door Hardtop hatchback from regular Mini Cooper versions. The range on a single charge should be at least 200 miles.

Sebastian Mackensen, global head of Mini, told industry trade journal Automotive News earlier this year that the brand's fifth "superhero" model will be an all-electric vehicle, saying that the car would be more than a token offering.

While declining to give any details on the new model's size, range, or powertrain, Mackensen said, "The electric car is not meant to just have an offering so you can say you have an electric car, but really nobody buys it. No, it is a real car."

MINI E electric cars used in vehicle-to-grid test. Photo by University of Delaware/Evan Krape

The Mini E's debut may be possible with the arrival of Samsung 125-Ah "low-height pack" battery cells, scheduled to come to market only in 2019. Those cells could give the electric Mini Cooper a rated electric range of 200 miles or more in a smaller pack than is possible today.

Mini has dabbled with electric variants in the past, most notably with the Mini E, a short-lived conversion of the 2009-2010 Mini Cooper three-door hatchback, which gave a range of around 100 miles from its 35-kilowatt-hour lithium-ion battery pack.

In the U.S., the Mini E was offered solely for lease to U.S. drivers in Los Angeles, New York, and New Jersey, but its main goal wasn't to bring electrification to the masses. (Some of that series remain on the road as research vehicles.)

Instead, was to be a test bench for the early development of hardware that would eventually find its way into the pioneering BMW i3 electric car launched in late 2013.

Some eight years on, BMW is no stranger to electric vehicles, with a growing array of plug-in hybrid versions of its mainstream models along with the i3 hatchback and the i8 plug-in hybrid sport coupe.

There's also a plug-in hybrid version of the new Mini Countryman crossover utility vehicle on the way.